First rangewide density estimate of the endemic and isolated Luangwa giraffe in Zambia

The Luangwa giraffe (Giraffa tippelskirchi thornicrofti), a subspecies of the Masai giraffe endemic to the Luangwa Valley of northeastern Zambia, inhabits an increasingly human-modified landscape. Accurate and current population estimates are critical to evaluating their status and identifying effective conservation strategies. However, sparse monitoring since the early 1900s has limited inferences about population size, structure, and range. To address this, we conducted the most spatially extensive and systematic survey to date of Luangwa giraffe across its distribution, extending survey effort 120 km south of their officially recognized extent. Using spatial capture recapture modeling, we estimated 651-890 giraffe and an overall density of 0.04-0.05 giraffe/km². Density decreased to nought beyond 7.5 km from permanent rivers, consistent with preferred forage concentrated in riparian areas. Increasing giraffe density estimates up to a threshold of the Human Footprint Index suggested that limited human presence may have negligible consequences on movement and resource selection. This was likely due to suitable habitat and minimal conflict despite human presence. However, without mitigating land-use planning, rapid land conversion threatens human-giraffe coexistence. An even sex ratio and small proportion of subadults implied a stable population, but sex-biased and temporal dynamics in space use, impacts of predation, and stochastic risks necessitate continued monitoring. This study highlights the value of systematic large-scale monitoring and opportunities for data integration across long-term monitoring programs to evaluate factors driving Luangwa giraffe dynamics and to inform science-based conservation of this unique and isolated population.